The Earth witnesses over 50 meteor showers a year, including the Geminid meteor shower. Image credit: NASA/Jeff DaiAsked by Ricky BerwickThe short answer is we don’t know. There is an abundance of space rocks that hit our atmosphere and disintegrate without a trace, making the answer indeterminable. Most space rocks we encounter are remnants of a comet or asteroids, but only an estimated five to ten per cent of these get past our atmosphere.When a space rock enters the Earth’s atmosphere, it is then called a meteor. We have over 50 meteor showers in a calendar year, a couple of the most famous meteor showers being the Geminids and the Perseids, where you can see up to 100 meteors every hour.The meteors that reach our surface are then called meteorites, and these again cannot be accurately tallied as they could reside in dangerous environments. Such places include oceans, jungles or deserts.Keep up to date with the latest news in All About Space – available every month for just £4.99. Alternatively you can subscribe here for a fraction of the price!